Differences in cortical actin structure and dynamics document that different types of blebs are formed by distinct mechanisms
Differences in cortical actin structure and dynamics document that different types of blebs are formed by distinct mechanisms
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DOI：
10.1006/excr.2002.5552
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发表时间：
2002-07-15
影响因子：
3.7
通讯作者：
Hagmann, J
中科院分区：
文献类型：
--
作者：
Keller, H;Rentsch, P;Hagmann, J
通过专门针对控制该过程的主要因素，如微管分解，局部肌动蛋白解聚和压力增加，研究了水泡形成。在表达绿色荧光蛋白-肌动蛋白的活极化细胞和/或在固定和染色的细胞中，可以记录由不同机制形成的至少两种不同类型的水泡（1型和2型）和可能的第三种类型（3型）。1型泡（膜/皮质解离泡）由质膜从皮质肌动蛋白解离形成，形成与限制环相关的细胞质肌动蛋白层。它们可以被微管分解剂秋水仙素诱导。2型泡（皮质肌动蛋白分解泡）在存在latrunculin A的情况下在皮质肌动蛋白层分解后形成。没有细胞质肌动蛋白层的限制环出现在细胞体的完整皮质肌动蛋白层和滤过泡的受损肌动蛋白层之间的过渡区。第三种类型的水泡（3型）的证据，显示一个完整的皮质肌动蛋白层，但没有细胞质肌动蛋白层和肌动蛋白细胞骨架和限制环之间没有可识别的关系，已经获得了被动细胞变形的微量移液器，这增加了压力。皮质肌动蛋白层的再聚合不一定导致滤过泡回缩。一旦形成，限制环不会变窄，这表明它们是等长收缩的结果。一个简化的分类方案已被开发出来，将水泡的类型与特定的信号或细胞功能联系起来。它的应用表明，自发起泡细胞几乎完全形成1型水泡。(C)2002 Elsevier Science（美国）。
Bleb formation has been studied by specifically targeting major factors controlling this process, such as microtubule disassembly, local actin depolymerization, and increased pressure. At least two different types of blebs (types 1 and 2) formed by different mechanisms and possibly a third type (type 3) can be documented at the front of living polarized cells expressing green fluorescent protein-actin and/or in fixed and stained cells. Type 1 blebs (membrane/cortex dissociation blebs) formed by dissociation of the plasma membrane from cortical actin develop cytoplasmic actin layers associated with restriction rings. They can be induced by the microtubule-disassembling agent colchicine. Type 2 blebs (cortical actin disassembly blebs) form after disassembly of the cortical actin layer in the presence of latrunculin A. Restriction rings without a cytoplasmic actin layer occur in a transition zone between the intact cortical actin layer of the cell body and the compromised actin layer of the bleb. Evidence for a third type of bleb (type 3), showing an intact cortical actin layer but no cytoplasmic actin layer and no recognizable relationship between the actin cytoskeleton and the restriction ring, has been obtained by passive cell deformation in micropipettes, which increases pressure. Repolymerization of the cortical actin layer does not necessarily result in bleb retraction. Once formed, restriction rings do not narrow, suggesting that they result from isometric contraction. A simplified classification scheme has been developed to relate the type of bleb to specific signals or cell functions. Its application shows that spontaneously-blebbing cells form almost exclusively type 1 blebs. (C) 2002 Elsevier Science (USA).